There has been a greater and greater demand for devices that are compact and highly functional to accommodate today's mobile and dynamic lifestyles. For instance, computing devices, including laptop computers and personal digital assistants (PDAs) are already very compact and mobile while still being able to offer the same types of functionality offered by their bigger brethren.
In recent years, there has also been a trend to make other devices, such as peripheral devices associated with these computing devices, similarly more compact and mobile. Such devices include printers or printing devices. A printing device, as described herein, refers to single function devices, such as copiers or fax machines, or multifunction devices, such as printer/copy/scan/fax machines. These printing devices typically have at least two functions that they must perform. First, they must be able to scan or copy (herein “scan”) original media such as original documents embodied in, for example, sheets of written or printed paper. Second, they must be able to print onto blank media, such as blank sheets of paper.
Recently, printing devices having common feed paths have been proposed. These devices use only a single input path to process both original media (i.e., scan or copy the original media) and blank media (i.e., print onto the blank media). One drawback associated with these common feed path printers is that they are unable to automatically distinguish between original media from blank media or blank sheets that are being fed to the common feed path.